This invention relates to a blow molding machine usable when a hollow-molded product is manufactured by a blow molding process, and more particularly to a dual reciprocating type blow molding machine having two mold-clamping devices.
A blow molding machine 100 shown in FIG. 13 is known as a dual reciprocating type blow molding machine having two mold-clamping devices. This blow molding machine 100 includes an extruding device 120, one pair of mold-clamping devices 130, 130xe2x80x2, and hammering devices 140, 140xe2x80x2 for hammering blow pins 141, 141xe2x80x2 respectively into molds 131, 131xe2x80x2 in the one pair of mold-clamping devices 130, 130xe2x80x2. For blowing, a parison P extruded from a cross head 121 of the extruding device 120 is clamped by alternately switching the mold-clamping devices 130, 130xe2x80x2 and then, the blow pins 141, 141xe2x80x2 are hammered into the molds 131, 131xe2x80x2 by the hammering devices 140, 140xe2x80x2, respectively.
By the way, in the above-mentioned conventional blow molding machine 100, since the one pair of mold-clamping devices 130, 130xe2x80x2 are linearly arranged in a perpendicular direction (z-direction of FIG. 13) to an opening- and closing-direction (direction piercing into the paper surface of FIG. 13) of the molds in the mold-clamping devices 130, 130xe2x80x2, it is necessary to provide two devices at both sides thereof for taking out a molded product after molding. It is also necessary to provide two systems of equipment for transferring molded products after they are taken out. Moreover, it is necessary that the mold-clamping devices 131, 131xe2x80x2 are in standby positions with an interval equal to or more than the width of a platen so that they are not interfered with each other when they stop under the cross head 121. This arrangement makes it necessary to increase a moving quantity of the mold-clamping devices. Accordingly, there is such a problem that an area for installing the machine is inevitably increased. Furthermore, since the hammering devices 141, 141xe2x80x2 are provided to perform a hammering operation from above the standby positions of the mold-clamping devices 130, 130xe2x80x2, inconveniences arise in view of layout when an increased number of extruding devices 2 are required in accordance with change in composition of the parison P or when an in-mold labeler is installed to perform an in-mold labeling.
It is, therefore, the first object of the present invention to provide a blow molding machine in which a device for taking out a molded product can be single in system and an area required for installing a machine can be reduced extensively. It is the second object of the present invention to provide a blow molding machine in which extruding devices can be increased in number and in-mold labelers can be arranged without any inconveniences in view of layout.
According to a feature of the present invention, there is provided, in order to achieve the first object, a blow molding machine comprising an extruding device, one pair of mold-clamping devices, and hammering devices for hammering blow pins respectively into molds in the one pair of mold-clamping devices, for blowing, a parison extruded from the extruding device being clamped by alternately switching the mold-clamping devices and then, the blow pins being hammered into the molds by the hammering devices, respectively, wherein the one pair of mold-clamping devices are linearly arranged in the same direction as an opening- and- closing direction of the molds in the mold-clamping devices.
According to a further feature of the present invention, there is provided, in order to achieve the first and second objects, a blow molding machine, wherein the hammering devices are each supported by tie bars or platens in each of the one pair of mold-clamping devices, and the blow pins are hammered respectively into the molds from under the molds by the hammering devices.
In the blow molding machine of the present invention, the parison extruded from the extruding device is clamped by alternately switching the one pair of mold-clamping devices and the blow pins are hammered respectively into the molds by the hammering devices for blowing. Since the one pair of mold-clamping devices are linearly arranged in the same direction as the opening-and-closing direction of the molds in the mold-clamping devices, the taking-out device can be provided only on one side of the mold-clamping devices. Accordingly, a molded product can be taken out by a single system and an area required for installing the machine can be reduced extensively.
In the blow molding machine of the present invention, since the hammering devices are each supported by the tie bars or the platens in each of the mold-clamping devices and the blow pins are hammered from under the molds, no inconvenience arises in view of layout when additional number of the extruding devices are employed in accordance with change in composition of the parison or when an in-mold labeler is installed to perform an in-mold labeling.